Figure 4.

Subcellular localization of Arabidopsis PMP22 in leaf tissue by differential centrifugation. Arabidopsis leaves were fractionated as described in Methods. Equal amounts of protein (120 μg) were separated by SDS-PAGE, transferred to nitrocellulose, and probed with affinity-purified antibodies against PMP22 (A) or the 23-kD protein of the PSII oxygen-evolving complex (B). C, Catalase activity, a peroxisomal matrix marker (shaded bars) and chlorophyll (white bars) were measured in each fraction. Catalase recovery was 102% and chlorophyll recovery was 61%. Lane 1, Homogenate; lane 2, 1,000g supernatant; lane 3, 1,000g pellet; lane 4, 25,000g supernatant; lane 5, 25,000g pellet.